Currently available lead-based paint abatement technologies result in the emission of hazardous lead dust as well as the generation of hazardous waste. Environmental contamination by fugitive dust emissions is regulated under the Clean Air Act while the Resource Conservation and Recovery Act addresses the proper disposal of lead-bearing wastes.

The technical objective of this project was (1) to develop and demonstrate novel vitrification technology using thermal spray and microwave energy for lead-based paint removal and disposal that can be used effectively for immobilization of heavy metal hazardous waste and (2) to evaluate emerging technologies for lead-based paint abatement including in-place management, sponge blasting, environmentally friendly chemical strippers, and cryogenic blasting.

The technical approach for the first objective involved the preparation of vitrified materials and determining how the hazardous waste is incorporated within the glass structure and immobilized. Vitrification and ion-leaching processes were modeled to optimize hazardous waste immobilization. This model was used to engineer durable, designer glass compositions for vitrification of lead-based paint. The application process involves using thermal spray of molten salt or microwaves for brick, masonry, concrete, and wooden structures. The approach for the second objective was to evaluate the efficacy and cost-effectiveness of emerging technologies for in-place management and removal of lead-based paint including cryogenic blasting, environmentally friendly chemical strippers, sponge blasting, and laser stripping. A decision tree was developed to select the optimum technology for lead-based paint hazard mitigation.

The synergistic combination of microwaves and chemical strippers has been evaluated for hard painted surfaces. A microwave applicator was fabricated and tested in the laboratory for paint removal efficiency on painted wood specimens, using graphite as the microwave enhancer. The temperature needed to soften the lead based paint by microwaves for easy removal was about 100°C. By using a cementitious coating in the calcium silicate-based PreTox 2000, the fire hazard was reduced and nonhazardous waste product was obtained. Toxicity characteristic leachate procedure testing revealed that the paint scrapings from this process leached less than 5 parts per million (ppm) lead. The thermal spray vitrification process was developed for leadbased paint removal and processing parameters were optimized. Lead-based paint was removed successfully from steel in the laboratory and the collection and remelting of the steel resulted in non-hazardous waste. This project was completed in FY 1998 and transitioned to the Environmental Security Technology Certification Program.

The research and development of lead-based paint abatement technologies reduces the cost of lead-based paint hazard mitigation, which is estimated to exceed $1 billion for Department of Defense (DoD) installations. The most significant benefit of this work is the optimized management of lead-based paint hazards and the increased protection of the health of DoD personnel and their families. Enhanced quality of life for the soldiers and their families leads to increased troop retention and a more capable force.